Table 2 Minimum inhibitory concentration (MIC), minimum microbicidal concentration (MMC), mean values of inhibition halos (M∅_h mm) and selectivity index (SI) obtained from in vitro antimicrobial susceptibility testing and cytotoxicity assays of the lyophilized extracts of S. praealtum

MIC/MMC

M∅_h

IC₅₀

SI

MIC/MMC

M∅_h

IC₅₀

SI

MIC/MMC

M∅_h

IC₅₀

SI

M∅_h

M∅_h

E. coli

25/−

0^A

4.22

0.17

25/−

0^A

5.96

0.24

−/−

0^A

–

–

12.3^D

na

E. aerogenes

50/−

0^A

4.22

0.08

−/−

0^A

–

–

−/−

0^A

–

–

9.7^C

na

S. marcescens

25/50

0^A

4.22

0.17

−/−

0^A

–

–

−/−

0^A

–

–

11.3^D

na

P. aeruginosa

25/−

0^A

4.22

0.17

−/−

0^A

–

–

−/−

0^A

–

–

11.3^D

na

P. mirabilis

25/−

0^A

4.22

0.17

−/−

0^A

–

–

50/50

0^A

–

> 1*

9.3^C

na

S. typhimurium

25/−

0^A

4.22

0.17

−/−

0^A

–

–

−/−

0^A

–

–

10.3^C

na

B. subtilis

50/−

0^A

4.22

0.08

50/−

0^A

5.96

0.12

25/25

7.7^C

–

> 1*

13.7^D

na

B. cereus

25/−

7^C

4.22

0.17

25/−

6.3^C

5.96

0.24

12.5/−

8.7^C

–

> 1*

13^D

na

M. luteus

12.5/50

7.3^C

4.22

0.34

25/50

4^B

5.96

0.24

12.5/50

10.3^C

–

> 1*

16^E

na

E. faecalis

25/−

0^A

4.22

0.17

25/−

0^A

5.96

0.24

12.5/−

0^A

–

> 1*

14.3^D

na

S. aureus

25/50

0^A

4.22

0.17

25/−

6.3^C

5.96

0.24

12.5/50

8.7^C

–

> 1*

13.3^D

na

Yeasts

C. albicans

–

0^A

–

–

–

0^A

–

–

25/−

0^A

–

> 1*

13.3^D

na

S. cerevisiae

6.25/50

0^A

4.22

0.68

12.5/50

6.7^C

5.96

0.90

6.25/50

8.7^C

–

> 1*

12.7^D

na

Mycobacteria

M. tuberculosis

na

0^a

na

na

na

0^a

na

na

na

0^A

na

na

na

11^D

M. bovis

na

0^a

na

na

na

0^a

na

na

na

0^A

na

na

na

11^D